About 6 p.m., police responded to domestic disturbance call from a home in the 2500 block of West 50th Street, according to a statement from the Chicago Police Office of News Affairs. The incident involved a violation of an order of protection, the statement said.

When police arrived, the man was on the front porch holding a baby and a backpack, and he told officers he had a gun in the backpack, the statement said.

While the man was on the porch, a male relative stepped outside and “an altercation ensued between the two,” according to the statement. The fight continued inside the home, and a person who lived in the house took charge of the baby.

Police followed the two men inside, where the man who had the backpack picked up multiple knives and threatened police and the relative, the statement said.

Officers ordered the man to put the knives down, and he moved toward police “in an aggressive manner.” Police opened fire on the man “in fear for the life of officers and occupants in the residence,” killing him, according to the statement from police.

Hector Hernandez, 21, of the 5200 block of South Maplewood Avenue, was dead at the scene, the Cook County Medical examiner’s office said.